Journal of Hazardous Materials, Vol.313, 9-17, 2016
Influence of microwaves on the leaching kinetics of uraninite from a low grade ore in dilute sulfuric acid
This paper describes a study on microwave assisted leaching of uranium from a low-grade ore of Indian origin. The host rock for uranium mineralization is chlorite-biotite-muscovite-quartzo-feldspathic schist. The dominant presence of siliceous minerals determined leaching of uranium values in sulfuric acid medium under oxidizing conditions. Process parametric studies like the effect of sulfuric acid concentration (0.12-0.50M), redox potential (400-500 mV), particle size (600-300 mu m) and temperature (35 degrees-95 degrees C) indicated that microwave assisted leaching is more efficient in terms of overall uranium dissolution, kinetics and provide relatively less impurities (Si, Al, Mg and Fe) in the leach liquor compared to conventional conductive leaching. The kinetics of leaching followed shrinking core model with product layer diffusion as controlling mechanism. (C) 2016 Elsevier B.V. All rights reserved.